Pacific Northwest Atmospheric River

Multiple low pressure systems have hit the North American West Coast over the past week. The latest system is set to bring an impactful atmospheric river event to parts of the Pacific Northwest.

Atmospheric rivers are classified by extensive rain, which soaked the Pacific Northwest alongside unseasonably warm temperatures and river flooding.

The U.S Coast Guard had to rescue five people from flooded areas around Portland, Oregon on Dec. 3. Another rescue had to be performed in southwest Washington, after four feet of water submerged his house.

Parts of Washington, including Seattle, Forks and Hoquaim received their highest rainfall on record for the season, with 1.5 inches of rain falling in Seattle.

A small landslide caused closures to a trail outside Seattle, and rivers also experienced extensive flooding in Washington and Oregon.

 

Visit the National Weather Service for more forecast details.

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Contributions by: Dakota Smith, Kim Erickson and Josh Reiter

Satellite imagery of this event:

Hover over the boxes to play. Click the images to view enlarged

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Full of Evolution of the Atmospheric River

Description:

This multi-day time lapse shows the full evolution of the low pressure system and resulting atmospheric river in the Pacific Northwest.


Phenomena: Atmospheric Rivers Flooding Mid-latitude Cyclones

Satellite: GOES-18

Product: Water Vapor (band 9)

Instrument: ABI

Mini Swirls within Larger Low-Pressure System

Description:

In the Gulf of Alaska, polar-orbiting satellites captured small swirls inside of the low-pressure that brought the plume of moisture to the PNW.


Phenomena: Atmospheric Rivers Mid-latitude Cyclones

Satellite: NOAA-20 NOAA-21 S-NPP

Product: Visible (I1)

Instrument: VIIRS

Multiple Systems Line Up to Feed Moisture into the West Coast

Description:

Multiple systems across the Pacific Ocean continue to feed moisture into the West Coast. Heavy rain is expected across northern California and western Oregon for the next few days.


Phenomena: Atmospheric Rivers

Satellite: GOES-18

Product: Airmass (EUMETSAT)

Instrument: ABI

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Pineapple Express Bombards Pacific Northwest with Heavy Rain

Description:

The risk of flash flooding and river flooding stricken the region as multiple inches of precipitation fall in a short period of time.


Phenomena: Atmospheric Rivers

Satellite: GOES-18

Product: Infrared (band 13)

Instrument: ABI

Mid-Latitude Cyclone Briefly Reveals Itself in Winter Sun

Description:

A large mid-latitude cyclone in the North Pacific briefly reveals itself in the winter sun.


Phenomena: Atmospheric Rivers Mid-latitude Cyclones

Satellite: GOES-18

Product: Visible (band 2)

Instrument: ABI

Deep Upper-Level Trough Directs Moisture Plume at the Pacific Northwest

Description:

A plume of moisture is being directed at the Pacific Northwest by a deep upper-level trough. Heavy rainfall and instances of flooding are expected in areas of Washington, Oregon, and Northern California over the next few days.


Phenomena: Atmospheric Rivers Mid-latitude Cyclones

Satellite: GOES-18

Product: GeoColor

Instrument: ABI

High Impact Atmospheric River Approaches Pacific Northwest

Description:

A high impact atmospheric river approaches the Pacific Northwest.


Phenomena: Atmospheric Rivers Mid-latitude Cyclones

Satellite: GOES-18

Product: Airmass (EUMETSAT)

Instrument: ABI

Impressive Low Pressure System Swirls over North Pacific

Description:

An impressive low pressure system swirls over the North Pacific as it approaches the Pacific Northwest coast.


Phenomena: Atmospheric Rivers Mid-latitude Cyclones

Satellite: GOES-18

Product: GeoColor

Instrument: ABI

String of Systems Hit North American West Coast

Description:

A string of low pressure systems approach the North American West Coast.


Phenomena: Mid-latitude Cyclones

Satellite: GOES-18

Product: GeoColor

Instrument: ABI